package com.zy.config;

import javax.servlet.*;

import com.alibaba.druid.filter.FilterChain;
import com.alibaba.druid.util.Utils;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.io.IOException;

//@Configuration
//@AutoConfigureAfter(DruidDataSourceAutoConfigure.class)
public class DruidConfig {

    /**
     * 带有广告的common.js全路径，druid-1.1.14
     */
    private static final String FILE_PATH = "support/http/resources/js/common.js";
    /**
     * 原始脚本，触发构建广告的语句
     */
    private static final String ORIGIN_JS = "this.buildFooter();";
    /**
     * 替换后的脚本
     */
    private static final String NEW_JS = "//this.buildFooter();";

    /**
     * 去除Druid监控页面的广告
     *
     * @param properties DruidStatProperties属性集合
     * @return {@link FilterRegistrationBean}
     */
//    @Bean
//    @ConditionalOnWebApplication
//    @ConditionalOnProperty(name = "spring.datasource.druid.stat-view-servlet.enabled", havingValue = "true")
//    public FilterRegistrationBean<RemoveAdFilter> removeDruidAdFilter(
//            DruidStatProperties properties) throws IOException {
//        // 获取web监控页面的参数
//        DruidStatProperties.StatViewServlet config = properties.getStatViewServlet();
//        // 提取common.js的配置路径
//        String pattern = config.getUrlPattern() != null ? config.getUrlPattern() : "/druid/*";
//        String commonJsPattern = pattern.replaceAll("\\*", "js/common.js");
//        // 获取common.js
//        String text = Utils.readFromResource(FILE_PATH);
//        // 屏蔽 this.buildFooter(); 不构建广告
//        final String newJs = text.replace(ORIGIN_JS, NEW_JS);
//        FilterRegistrationBean<RemoveAdFilter> registration = new FilterRegistrationBean<>();
//        registration.setFilter(new RemoveAdFilter(newJs));
//        registration.addUrlPatterns(commonJsPattern);
//        return registration;
//    }

    /**
     * 删除druid的广告过滤器
     *
     * @author BBF
     */
//    private class RemoveAdFilter implements Filter {
//
//        private final String newJs;
//
//        public RemoveAdFilter(String newJS) {
//            this.newJs = newJS;
//        }
//
//        @Override
//        public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
//                throws IOException, ServletException {
//            chain.doFilter(request, response);
//            // 重置缓冲区，响应头不会被重置
//            response.resetBuffer();
//            response.getWriter().write(newJs);
//        }
//    }
}
